Cementitious floating screeds are commonly used in Belgian residential buildings to meet the national standard criteria for impact sound insulation. Reliable data for the improvement of impact sound insulation of these floating floors are an essential prerequisite for a correct estimation of the achievable performance in situ. Laboratory measurements according to ISO 10140-3 are commonly performed for this purpose, albeit on assemblies that are not always in line with common practice. For instance, floating screeds usually contain ducts and pipes, such as for plumbing or electricity, which are completely lacking from laboratory test setups. The influence of these pipes on the improvement of impact sound insulation is investigated in a large measurement campaign at the BBRI acoustics laboratory. Different possible influence parameters are examined such as the number, diameter and embedding of the pipes, and this for different types of resilient underlays and levelling screeds. The research results should allow design and implementation guidelines to be developed that consider the acoustic impact of pipes in floating screeds. The paper summarizes the most recent findings of the study in progress. DOC_METADES:Influence of ducts on the impact sound insulation of floating screeds: the paper summarizes the most recent findings of the study in progress. DOC_METADES_NL: CST_DETAIL_CONTENU: CST_DETAIL_LEGENDE: CST_DETAIL_LEGENDE2: CST_DETAIL_LEGENDE3: CST_DETAIL_LEGENDE4: CST_DETAIL_LEGENDE5: CST_DETAIL_LEGENDE6: